For Fox News, the smoking gun in the Internal Revenue Service scandal came in the form of analysis from one of Washington's most famous pundits.

Mark Halperin, the bestselling author and regular guest on MSNBC's "Morning Joe," appeared Monday on the sunrise gabfest and wound up providing fodder to a rival cable news channel.

Halperin said that, if a Republican president were in the White House, the national press would be far more interested in why two years' of emails sent and received by Lois Lerner, the ex-IRS official embroiled at the center of the scandal, went missing.

“I think with a different administration, one that was a Republican administration, this story would be a national obsession and, instead, it's getting coverage here and a few other places, but it really deserves a lot more questions," Halperin said.

The analysis provided all of the necessary ingredients for a Fox News feast. Here was a member of the mainstream media appearing on a left-leaning network and calling out the press for liberal bias.

"Whoa," Fox host Stuart Varney said on "Your World" after playing the clip on-air Tuesday. "What does it say when an MSNBC panelist says that?"

Varney then welcomed conservative media watchdog L. Brent Bozell III, who called Halperin's comment "a breath of fresh air." Bozell also credited National Journal's Ron Fournier, who said this week that an independent prosecutor should investigate the missing emails.

In the next hour, the crew on "The Five" eagerly cited Halperin and Fournier.

Later in the evening, conservative columnist Charles Krauthammer, appearing on "Special Report," pointed to Halperin's words as evidence that the missing emails are "very serious."

"And the only reason the administration is not getting pilloried on this is because of the press," Krauthammer said. "Even Mark Halperin talked about this this morning, who is hardly a right-wing zealot. [He] said if this were a Republican president there would be screaming headlines."